The disclosure of Japanese Patent Application No. HEI 12-086770 filed on Mar. 27, 2000 including the specification, drawings and abstract is incorporated herein by reference in their entirety.
1. Field of the Invention
This invention relates to improvement of a method of manufacturing oxygenated fuel to be used for diesel engines etc.
2. Description of Related Art
Conventionally, a diesel fuel that has outstanding lubricity, oxidation stability, and a high cetane number has been desired. For example, Japanese Patent Publication for PCT No. HEI 11-513730 (note: WO97/14769) discloses a manufacturing method of such a diesel fuel.
In the conventional technology, hydrocarbons that are obtained from a synthesis gas (mixture of hydrogen and carbon monoxide) through Fischer-Tropsch process (hereinafter abbreviated as xe2x80x9cFT processxe2x80x9d), whose main component is paraffin, are separated into a light fraction and a heavy fraction. The heavy fraction is subjected to isomerization treatment while the light fraction is not subjected to the aforementioned treatment.
Incidentally, as a catalyst to be used in the Fischer-Tropsch process, a catalyst formed from silica SiO2, alumina Al2O3, or the like impregnated with cobalt is in use.
In the conventional manufacturing method of diesel fuel, the light fraction is directly mixed as it is with the heavy fraction that has been subjected to the isomerization treatment. Because the light fraction has a high ratio of olefin, when it is used in diesel fuel, it results in a large generation of soot when the diesel fuel is combusted.
In view of the foregoing conventional problem, it is an object of the invention to provide a method of manufacturing an oxygenated fuel that excels in lubricity, oxidation stability, and has a high cetane number and that can suppress the generation of soot.
To achieve this object, the invention provides a method of manufacturing an oxygenated fuel wherein, by reacting an olefin with the synthesis gas using a solid catalyst to induce an oxo process, oxygenates are synthesized.
Moreover, in the method of manufacturing the oxygenated fuel, the olefin may be obtained from the synthesis gas through the Fischer-Tropsch reaction.
Since the oxygenated fuel manufactured in this way contains mainly oxygenates such as alcohol and aldehyde the oxygenated fuel has excellent lubricity and oxidization stability and has a high cetane number as well as the capability to suppress the generation of soot effectively when the oxygenated fuel is combusted.